Layout of an electrical power system provided with a fuel cell in an electric vehicle

ABSTRACT

An electrical power generating system in an electrical vehicle has a first module for preprocessing and metering of the gases to be supplied to a fuel cell, a second module with the fuel cell, and an electrical power distribution module. The first module and the second module are mounted in a container, which is then installed in the electrical vehicle from underneath, in a cavity provided for this purpose. The electrical power distribution module is then attached to the outside of the container.

This application claims the priority of German patent document 102 49437.1, filed Oct. 24, 2002 (PCT International Application No.PCT/EP2003/010513, filed Sep. 20, 2003), the disclosure of which isexpressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to an electrical power generating system thatincludes at least one electrical traction motor, a fuel cell, and meansfor supplying the fuel cell with a combustion gas and an oxidizing gas,in an electric vehicle that has a load-bearing structure withlongitudinal supports.

German patent document DE 4 412 450 A1 discloses a vehicle with such anelectrical power generating system. The vehicle has a chassis thatincludes two longitudinal supports and two transverse supports, withfront and rear axles articulated on the longitudinal supports. Theelectrical traction motor is arranged on the front axle, and isconnected to an electrical power controller which is fed from the fuelcell that includes a stack of individual fuel cells. A reformer, a fueltank and additional units such as ion interchangers, condensationseparators, reformat coolers, heat exchangers, temporary hydrogen storesand fuel cell coolers are provided in order to produce the combustiongas. The oxidizing gas is fed into the fuel cell using a compressorwhich is preceded by an air filter.

One object of the present invention is to provide an electrical powergenerating and distribution system for an electric vehicle, whichcontains prefabricated parts with which the vehicle can quickly beequipped.

Another object of the invention is to provide a method for simpleinstallation of such an electric power generating system in an electricvehicle.

These and other objects and advantages are achieved by the electricpower generating system according to the invention, which contains afirst module with appliances at least for preprocessing and metering ofthe gases to be fed into the fuel cell and a second module with the fuelcell itself. The fuel cell is connected to the first module bymechanical coupling means, for carrying the gases to be supplied to thefuel cell, dissipating reaction gases from the fuel cell, and carryingat least one coolant via the fuel cell, and by electrical couplingelements, which transmit measured values from sensors.

The first module and the second module are jointly mounted in acontainer which can be inserted into a cavity in the vehicle (accessiblefrom the underneath side), and can be attached to the longitudinalsupports in the vehicle by at least four holders fitted to the containerlongitudinal side walls. An electrical power distribution module, whichincludes at least distribution circuits with fuses, and a switchingelement for switching the distribution circuits on and off, can beattached to a side wall of the container and can be connected viacoupling elements to the electrical outputs of the fuel cell and tocables to the electrical loads in the electrical vehicle.

The electrical power generating system according to the invention thushas three modules which can be produced autonomously. Two of the modulesare mounted within the container and the third is connected to an outerwall of the container. The first and second modules can be produced in aworkshop configured particularly for this purpose. The connectionsbetween the two modules can also be made there using a jig, based ontheir arrangement. The unit comprising the two modules connected to oneanother is then installed in the container. The assembly formed in thisway is suitable as a supply part.

The first module together with the appliances for preprocessing andmetering of the gases to be fed into the fuel cell is preferablyarranged at the front of the container, relative to the direction oftravel of the electrical vehicle, and is screwed to the bottom of thecontainer. This arrangement allows the module, which is also referred toin the following text as the gas preprocessing module, to be attachedquickly and easily.

In a further preferred embodiment, the second module (the “fuel cellmodule”) has a housing which contains the numerous individual fuel cellswith electrical connections. It is connected to the container by twoscrews at the rear container bottom and via one holder on each of theleft and right sides, alongside the front face. Particularly whendesigned for high electrical power levels, the fuel cell is relativelyheavy and is attached to the container at four points.

The third (electrical power distribution) module can be attached to anouter wall of the container, which is adjacent to the second module andruns transversely with respect to the longitudinal supports. Theelectrical power distribution module is lighter than the fuel cellmodule and the gas preprocessing module; it can therefore be handledmore easily and can also be attached to the container more easily afterthe latter has been installed in the electric vehicle.

It is also expedient to provide at least two holders with guide pins oneach of the two longitudinal faces of the container. The guide pins canthen be pushed into holes in the longitudinal supports in the electricalvehicle, and the holders can be attached to the longitudinal supports bymeans of screws, so that the two modules to be attached to the vehiclequickly and easily.

The holders preferably include movement restriction means, whichrestrict the movement of the container relative to the longitudinalsupports, and allow such movement only in the event of an impact beyonda specific impact strength. They may also have energy absorption meansfor controlled transmission of kinetic energy from the container to thelongitudinal supports, with energy being at least partially destroyed.

In the method according to the invention for mounting or installing anelectrical power generating system such as described above, in anelectrical vehicle which has a load-bearing structure with longitudinalsupports, a first module with appliances for preprocessing and meteringof fuel gases and a second module with the fuel cell are produced. Thesefirst and second modules are arranged in an apparatus and are thenconnected to one another by mechanical coupling elements, includinglines for the substances to be supplied to and from the fuel cell andcoolant routing for the fuel cell, and electrical coupling elements forsensor signal transmission between the two modules. The connectedmodules are then mounted in a common container, which is then inserted(together with the modules) into the electric vehicle from underneath,into a cavity provided for that purpose, and attached to thelongitudinal supports.

The third module, which contains an electrical connection for theelectrical outputs of the fuel cell, electric power distributioncircuits with fuses for connection of electrical loads, and at least oneswitching element for switching the electrical power distributioncircuits on and off, is then attached to the container externally on aside wall. The electrical connections are then made from the thirdmodule to the fuel cell and to electrical loads in the vehicle. Thefirst module is connected to a source of combustion gas and a channelfor air supply, and is connected by means of inputs and outputs to atleast one cooling circuit in the electrical vehicle and to output linefor the reaction products from the fuel cell.

The method according to the invention makes it possible to produce majorcomponents of the electrical power supply system in their own right,remote from the vehicle assembly location, and to join them together toform a self-supporting unit which can be transported to the vehicleassembly location, and installed in this vehicle quickly and easily.Overall, this reduces the amount of effort for assembly of the vehicle.

The gas preprocessing module is mounted in the front of the container,relative to the direction of travel, by two screws. The fuel cell moduleis expediently mounted by means of two screws in the rear part of thecontainer bottom, and by means of two holders, which are each arrangedon one face of the module on the longitudinal side walls of thecontainer. A mechanical interface between the gas preprocessing moduleand the fuel cell module includes inputs for hydrogen gas and air,inputs and outputs for at least one cooling medium, and outputs for thereaction products. An electrical interface is provided for the measuredvalues from pressure and temperature sensors. The coupling elements ofthe interfaces are produced in a jig after the arrangement andconnection of the gas preprocessing module and of the fuel cell module.The modules which have been connected to one another are then mounted inthe container.

The container together with the two modules is then installed in theelectrical vehicle by being pushed on a lifting device into a cavity inthe vehicle. It is then screwed to the longitudinal supports at fourholders, which are fitted to the longitudinal faces of the container.The electrical power distribution module, which contains connections forthe electrical outputs of the fuel cell and outgoing lines with fusesfor the connection of electrical loads in the vehicle, and an on/offswitch for the outgoing lines, is then attached to a wall of thecontainer which runs transversely with respect to the longitudinalsupports. The electrical connections are then made. Finally, connectionsare also made from a hydrogen source to an input on the gaspreprocessing module, from an air induction channel to the gaspreprocessing module, and from there to output lines for the reactionproducts of the fuel cell, to vent lines and to a coolant source.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an electric vehicle power generating systemaccording to the invention, which is composed of modules and is arrangedin a container;

FIG. 2 shows a perspective view from above the electrical powergenerating system of FIG. 1; and

FIG. 3 is a schematic front sectional view, taken through longitudinalsupports in an electrical vehicle having a container, which is attachedto the longitudinal supports, with modules of an electrical powergenerating system.

DETAILED DESCRIPTION OF THE DRAWINGS

As shown in FIGS. 1-3, an electrical power generating system 1 for anelectrical vehicle has a first module 2 with appliances forpreprocessing and metering of the gases to be fed into a fuel cell. Thegases are, for example, hydrogen as the combustion gas and air as theoxidizing gas. The module 2 has an input 3 for hydrogen which issupplied via a metering valve to the fuel cell, which is arranged in asecond module 4. (Conventional components, such as a compressor for theair, an air filter, sensors for the pressure, temperature and gas flowrates, and further components for the metering of hydrogen are providedin the module 2, but are not shown, for the sake of simplicity.)

The module 4 contains the fuel cell (which is in the form of a stack ofindividual fuel cell elements) with connections for the supply ofhydrogen, air, coolant, and outputs for the reaction products as well aselectrical connections for the emission of currents and measured valuesfrom sensors in the fuel cell. Interfaces for coupling elements areprovided between the two modules 2, 4, for the transmission of thecoolant, for example water, hydrogen gas, air and the reaction productsof the fuel cell. (Two such coupling elements 5, 6 are illustrated inFIG. 2.) Further electrical interfaces (also not illustrated), arelikewise provided for the transmission of measured values from sensorsarranged in the fuel cell, with the corresponding coupling elements. Inaddition to the fuel input 3, the module 2 has inputs and outputs forthe coolant, an input for air and at least one output for reactionproducts of the fuel cell. (Two such inputs and outputs 7, 8 areillustrated in FIG. 2.)

The two modules 2, 4 are jointly arranged in a container 9, in the formof a trough whose bottom forms a part of the lower face of the electricvehicle. The module 2, together with the appliances for thepreprocessing and metering of the gases, is mounted by means of screws11 on the bottom 10 of the container 9 at the front, relative to thelongitudinal direction of the vehicle. The module 4, which has a housingthat contains the individual fuel cell elements (not illustrated) isscrewed to the bottom 10 of the rear part of the container 9 by means oftwo screws 12. Furthermore, the module 4 is attached by means of screws14 to the side walls of the container 9 via two holders 13 which arelocated at the side on the left and right of the front surface of thecontainer 9.

The third module 15 (also referred to as electrical power distributionmodule), contains connections for the electrical outputs of the fuelcell and outgoing with fuses for the electrical loads on thehigh-voltage network that is fed from the fuel cell (for example, 200V-400 V in the electrical vehicle), and at least one on/off switch forthe outgoing. Relative to the forward direction of travel of thevehicle, the module 15 is attached on the outside of the rear wall 16 ofthe container 9. This wall 16 is adjacent to the module 4. Two or moreplug connector elements, (for example, elements 18, 19 and 20) which arelocated on a wall 17 of the module 15, are provided for the connectingcables which lead to the loads on the high-voltage network.

Holders 21, 22 are attached respectively to the two longitudinal facesof the container 9 (that is, the faces which run transversely withrespect to the longitudinal supports in the vehicle), and for attachingthe electrical power generating system 1 to the vehicle. The holders 21,22 are attached by means of screws 23 to two longitudinal supports 24,25 of a load-bearing structure of the electrical vehicle. The holders21, 22 have guide pins 26 which project into corresponding holes (notillustrated in any more detail) in the longitudinal supports 24, 25 andare provided for rapid alignment of the container 9 with respect to thelocation of that attachment to the longitudinal supports duringassembly.

The holders 21, 22 are equipped with movement restriction means, whichrestrict the movement of the container 9 relative to the longitudinalsupports 24, 25, allowing such movement only in the event of an impactof the vehicle beyond a specific impact strength. Furthermore, theholders 21, 22 have energy absorption means for controlled transmissionof kinetic energy from the container 9 to the longitudinal supports 24,25, with at least partial energy dissipation. The holders 21, 22 have atype of framework, which allows oscillating movements of the typedescribed above. German patent document DE 197 38 620 C1 describes aconventional holder for a battery mount in an electrical vehicle, whichallows the movements described above and the energy dissipation in theevent of a crash.

The modules 2 and 4 may each be produced separately, with the componentsthat are not illustrated in detail being inserted into the modules andmounted therein. The necessary connections between the components arethen made in the modules 2 and 4. The two modules 2, 4 are then fixedand connected to one another in an apparatus, for example a jig. Oncethe coupling elements have been fitted between the two modules 2, 4, thelatter are inserted into the container 9. The module 2 is screwed to thebottom 10 of the container 9, at the front. At the rear, the module 4 isscrewed to the bottom 20 of the container, and to the side walls of thecontainer 9.

The container together with the modules 2, 4 is a robust unit which canbe transported on its own and which can be manufactured in particular asa supply part for an electrical vehicle. A heavier fuel cell is requiredin order to achieve more power. The container together with the modules2, 4 is placed on a lifting device and is raised from underneath into acavity (which is provided for this purpose) in the jacked-up electricalvehicle, until the guide pins 26 engage in the holes (not shown) whichare provided for this purpose in the longitudinal supports 24, 25, andthe holders 21, 22 rest on the longitudinal supports 24, 25. The holders21, 22 are then screwed to the longitudinal supports 24, 25.

The module 15 is then pushed from underneath in guide rails on the wall16 as far as a stop (not illustrated), and is attached to the wall 16 bymeans of screws. The contacts (which are not illustrated) on the fuelcell and on the module 15 are then connected to one another. Once themodule 15 has been fitted to the wall 16 of the container 9 that ismounted in the electrical vehicle, and once the electrical connectionsbetween the fuel cell and the module 25 have been made, the connectingline 28 for the hydrogen supply to the ‘1input 3, the lines to theinputs and outputs for air, the reaction products and cooling water arelaid. A high-temperature and a low-temperature cooling circuit can bearranged in the vehicle, both of which are passed to the modules 2, 4via the container. The means for provision of the hydrogen, for examplea hydrogen tank, will have already been fitted in the electrical vehiclebefore the installation of the electrical power supply system 1.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1-10. (canceled)
 11. An electrical power generating system for anelectric vehicle which has at least one electric traction motor, and aload-bearing structure with longitudinal supports; said electrical powergenerating system comprising: a first module that includes devices forpreprocessing and metering of gases to be supplied to a fuel cell; asecond module that includes the fuel cell; and an electric powerdistribution module, which includes distribution circuits with fuses andat least one switching element for switching the distribution circuitson and off; wherein, the fuel cell is connected to the first module bymechanical coupling means for carrying the gases to be supplied to thefuel cell, dissipating the reaction gases from the fuel cell, andcarrying at least one coolant via the fuel cell, and by electricalcoupling elements for transmitting measured values from sensors; thefirst module and the second module are jointly mounted in a containerthat is of such a size and shape as to be insertable into acorresponding cavity on an underneath side of the vehicle, and has atleast four holders which are fitted to the container side walls, forattaching to the longitudinal supports in the vehicle; and the electricpower distribution module can be attached to a side wall of thecontainer and can be connected via coupling elements to the electricaloutputs of the fuel cell and to cables to the electrical loads in theelectrical vehicle.
 12. The arrangement as claimed in claim 11, wherein,in an installed position, the first module, including the devices forpreprocessing and metering gases to be fed into the fuel cell, isarranged at a front area of the container, relative to a direction oftravel of the electric vehicle, and is screwed to the bottom of thecontainer.
 13. The system of claim 12, wherein the second module has ahousing that contains individual fuel cells with electrical connections,and is connected to the container by two screws at a rear bottom area ofthe container via one holder on the left and one holder on the right,alongside a front face of the container.
 14. The system of claim 13,wherein the electrical power distribution module is attachable to a wallon the outside of the container which wall is adjacent to the secondmodule and runs transversely with respect to the longitudinal supports.15. The system of claim 14, wherein: at least two holders are providedon each of two longitudinal faces of the container and have guide pinswhich can be pushed into corresponding holes in the longitudinalsupports in the electrical vehicle; and the holders can be attached tothe longitudinal supports by screws.
 16. The system of claim 15,wherein: the holders have movement restriction means, which restrict themovement of the container relative to the longitudinal supports, andallow such movement only in the event of an impact beyond a specificimpact strength; and the holders have energy absorption means forcontrolled transmission of kinetic energy from the container to thelongitudinal supports, with energy being at least partially dissipated.17. A method for installing an electric power generating system in anelectric vehicle which has at least one electric traction motor, and aload-bearing structure with longitudinal supports, said methodcomprising: producing a first module that includes devices forpreprocessing and metering of gases to be supplied to a fuel cell, asecond module that includes the fuel cell, and a third module, whichcontains an electrical connection for the electrical outputs of the fuelcell and electrical power distribution circuits with fuses for theconnection of electrical loads and at least one switching element forswitching the electrical power distribution circuits on and off;arranging the first and second modules in an apparatus, and connectingthem to each other by mechanical coupling elements that include linesfor the gases to be supplied to the fuel cell and gases to be dissipatedfrom it, and coolant routing for the fuel cell, and electrical couplingelements for signal transmission between the two modules; mounting theconnected first and second modules in a common container; inserting thecontainer, including the modules, into a corresponding cavity which isprovided in an underneath side of the electric vehicle; attaching thecontainer to the longitudinal supports; attaching the third moduleexternally to a side wall of the container; forming the electricalconnections from the third module to the fuel cell and to loads in theelectrical vehicle; connecting the first module to a source for thecombustion gas and to a channel for the air supply; and connecting thefirst module by means of inputs and outputs to at least one coolingcircuit in the electrical vehicle and to output line for the reactionproducts from the fuel cell.
 18. The method of claim 17, wherein thefirst module is mounted in the container by means of two screws at afront of the container, relative to a forward direction of travel of thevehicle.
 19. The method of claim 18, wherein the fuel cell module ismounted by means of two screws in a rear part of the container bottom,and one screw on each face of the module.
 20. The method of claim 19,wherein the third module is attached to a wall of the container which isadjacent to a module with the fuel cell, and runs transversely withrespect to the longitudinal supports.